One Step Hydrothermal Confined Growth of Ni ₃ V ₂ O ₈ on 3D GO/CNT Networks Toward High‐Performan

ABSTRACT

Binary transition metal oxides attract extensive attention due to outstanding electrochemical charge‐storage performance. As a typical bimetallic oxide, nickel vanadate (Ni ₃ V ₂ O ₈ ) possesses rich multivalent Ni/V redox sites and delivers high theoretical capacitance for supercapacitor electrodes. Herein, ternary Ni ₃ V ₂ O ₈ /GO/CNT was successfully fabricated via a facile one‐step hydrothermal strategy. GO and CNT self‐assemble into an interconnected 3D dual‐carbon network via van der Waals forces and π‐π stacking, which confines uniform in situ growth of Ni ₃ V ₂ O ₈ particles. The synergistic structural and conductive advantages endow the optimized Ni ₃ V ₂ O ₈ /GO/CNT electrode with a high specific capacitance of 882.5 F g ^{− 1} at 0.5 A g ^{− 1} . Coin‐cell symmetric supercapacitors (SSCs) were further assembled to evaluate the practical application potential of the Ni ₃ V ₂ O ₈ /GO/CNT. The SSC device works steadily at 0–1.5 V in 3 

KOH aqueous electrolyte, achieves a specific capacitance of 194.3 F g ^{− 1} at 0.5 A g ^{− 1} , and exhibits a maximum energy density of 36.8 Wh kg ^{− 1} at a power density of 375.2 W kg ^{− 1} . After 6000 charge‐discharge cycles, the device retains 89.6% of its initial capacitance, demonstrating excellent long‐term cycling stability. Two series‐connected coin cells successfully power a 2 V LED lamp, verifying its great potential for practical energy storage.